Application of Neck Ultrasound in the Diagnosis of

Mengjun Shen Tongji University Ying Zhou Tongji University Weiqing Gu Tongji University Chengsheng Yin Tongji University Yin Wang Tongji University Yuan Zhang (  [email protected] ) Tongji University

Research Article

Keywords: Sarcoidosis, cervical , ultrasound, CEUS,

Posted Date: August 2nd, 2021

DOI: https://doi.org/10.21203/rs.3.rs-692986/v1

License:   This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License

Page 1/15 Abstract

Objective: To explore the signifcance of neck ultrasound (NUS) combined with contrast-enhanced ultrasound (CEUS) in the diagnosis of sarcoidosis.

Methods: 88 patients with evidence of intrathoracic lymphadenopathy and suspected sarcoidosis with enlarged underwent NUS, CEUS, fne-needle aspiration (FNA) and core needle (CNB) when technically feasible were retrospectively analyzed in this study. Seven characteristics such as enhanced mode (EM), resolution time (RT), Color Doppler Flow Imaging (CDFI) , fading time (FT), peaking state-uniformity (PTSU), strengthen the area (STA) and symmetry were considered to perform the logistic regression model.

Results: Of 88 patients included in this study, sarcoidosis was accounted in 20 cases, tuberculosis in 23 cases, malignancy in 22 cases and infammatory in 23 cases. There were statistically signifcant differences in symmetry, lymphatic hilum, homogeneity, CDFI pattern and elasticity score between the sarcoidosis and non-sarcoidosis groups via NUS. Similarly, we also acknowledged a statistically signifcant differences in enhanced mode, homogeneity, presence or absence of necrosis between the sarcoidosis and non- sarcoidosis groups via CEUS to further group the non-sarcoidosis into tuberculosis, malignancy or infammatory disorder. The percentage correction of prediction was 90% (18/20).

Conclusion：NUS combined with CEUS has characteristic features in sarcoidosis with cervical lymph node involvement, which is helpful for its diagnosis and differential diagnosis. The binary classifcation model of NUS combined with CEUS features can help differentiate sarcoidosis from non-sarcoidosis groups.

Key Point

The NUS combined with CEUS is very essential for diagnosis of sarcoidosis from other granulomatous non-sarcoidosis lesions non- invasively.

Background

Sarcoidosis is a systemic disease of unknown etiology, with the pathological feature of non-caseous epithelioid granulomas. In addition to the lung and intrathoracic lymph nodes, many organs including cervical lymph node could be involved [1, 2]. Sarcoidosis is a diagnosis of exclusion because of its similarity in the clinical presentations to other lung diseases (such as tuberculosis, fungal infections, lung cancer, and cryptogenic organizing ) [3]. The confrmatory diagnosis of sarcoidosis is established only when clinic-radiographic fndings are supported by histological evidence of non-caseating granulomatous infammation with other causes of granulomas and local reactions have been reasonably excluded [2, 3]. China has a high prevalence of TB, which causes a signifcant challenge in differentiating sarcoidosis from other granulomatous lung diseases especially in cases of smear-negative for tuberculosis [4, 5].

Although great efforts have been devoted to establish methodologies that can differentiate sarcoidosis from other lung diseases [4–6], the diagnosis of sarcoidosis still requires histological confrmation to detect the presence of granulomatous infammation and also to exclude other potential causes of granulomatous infammation simultaneously. 10.8% of patients with sarcoidosis are reported to have enlarged cervical lymphadenopathy on ultrasound. And previous studies reported that NUS and FNA of cervical lymph nodes is a potential modality that can be used for the diagnosis of sarcoidosis patients [9–12].

Contrast-enhanced ultrasound (CEUS) is a new technique used for real-time assessment of tissue perfusion. It has been widely used to evaluate liver, kidney, pancreas, spleen, ovarian, thyroid, breast and prostate lesions in the current clinical practice. It has been widely performed in identifcation of sentinel lymph node in breast cancer patients [13–16].

CEUS helps radiologists investigate and characterize focal lesions. Its contrast pool, sensitivity and specifcity in diagnosing liver lesions are similar to contrast CT in contrary CT is more costly and involves higher levels of ionizing radiation exposure. Recently, CEUS has often been used to identify benign and malignant superfcial lymph nodes [17–19].

Previous studies have shown that CEUS has a higher sensitivity in identifying small blood vessel reductions or areas of multiple blood vessels that cannot be detected by Doppler technology leading to a better evaluation of LNS classifcation [20].

Page 2/15 Compared with CT and MRI, gray-scale ultrasound combined with CEUS can assess the shape, margins, internal structure, and vascularization of superfcial lymph nodes [21]. It improves the accuracy of ultrasound for diagnosis of superfcial lymph nodes disorders.

The main limitation of CEUS is the practice mode, because the interpretation of ultrasound images depends on technical skills and the experience of the radiologist. In addition, CEUS is not suitable for patients who have allergic reactions to contrast agents and pregnant women.

Therefore, this study intends to retrospectively analyze the CEUS qualitative diagnosis data of several groups of diseases involving cervical lymph nodes accounting factors such as the enhanced mode of ultrasound contrast agent, degree of enhancement, homogeneity, presence or absence of necrosis, arrival time, peak time, wash-out time, and so on. We aim to explore the characteristics that guide the diagnosis and differential diagnosis of sarcoidosis and provide a new non-invasive diagnostic methodology for sarcoidosis involving the cervical region.

Methods Study Design

This was a retrospective observational study. The study protocols were approved by the Institutional Review Boards of Shanghai Pulmonary Hospital (Approval No K18-144).

Patients and diagnostic criteria

Altogether 88 patients with tissue proven sarcoidosis, tuberculosis (TB), lung cancer or infammation were evaluated at the Shanghai Pulmonary Hospital between September 2018 and December 2019 were recruited for this study. All these patients manifested cervical lymphadenopathy and pathological diagnosis of their lymph node were consistent with their clinical diagnosis.

Conventional US (B-Mode and Doppler) NUS Examination

All of conventional ultrasound scans and CEUS examinations were performed by two senior clinical ultrasonographers with more than 3 years of experience in neck ultrasound (SMJ and WY). Conventional ultrasound scans were performed by a 6-15 MHZ probe (LOGIQ E9, GE, Wauwatosa, WI). A routine ultrasonography on the target lesion was performed by adjusting the focus and depth of the lesion, then selecting the best acoustic window to fully display the lesion boundary and fnally evaluating the symmetry of the lymph nodes (unilateral or bilateral), number (1 or > 1), longitudinal meridian (≥ 10 mm or <10 mm), aspect ratio (<2 or ≥2), lymphatic hilum (present or absent), border (clear or unclear), echo (hypoechoic or hyperechoic), homogeneity (uniform or non-uniform), calcifcation (present or absent), and fusion (present or absent). Color Doppler fow imaging (CDFI) and elastic imaging were performed after gray-scale ultrasound. The CDFI pattern of lymph nodes can be divided into four types: portal, dendritic, annular and others. The elasticity scoring was performed based on the elastography 5 points proposed by Itoh et al [22]. The cases were divided into two groups according to elasticity score (≥3 or <3). As shown in Table 2.

Contrast-enhanced ultrasound (CEUS) Examination

After conventional ultrasound, the largest diameter nodule was selected before switching to CEUS mode. CEUS was performed by a 3-9 MHZ probe (LOGIQ E9, GE, Wauwatosa, WI), and using a low mechanical index (MI <0.13). The contrast agent (SonoVue, Bracco SpA, Milan, Italy) was injected intravenously through the anterior cubital vein with a dose of 1.5 ml followed by bolus irrigation with 5 ml normal saline. The timer was started while injecting the contrast agent, followed by 3 minutes continuous observation and recording of data. It was also made sure that the image and condition settings remained unchanged during the entire imaging process. We observed and recorded the following indicators: the enhanced mode of ultrasound contrast agent (centripetal, centrifugal, polycentric, or annular), degree of enhancement (low, equal or high), homogeneity (uniform or non-uniform), necrosis (present or absent), and arrival time of contrast agent, peak time, and wash-out time.

Page 3/15 Fine-needle aspiration (FNA) and core needle biopsy (CNB)

Abnormal lymph nodes were defned based on a short axis diameter of ≥6mm. When technically feasible, FNA of lymph nodes was performed by a trained physician. If suitable, a core needle biopsy (CNB) was performed on the lymph node using a 18G*10cm biopsy needle (Duo smart, Gallini s.r.l, Italy). On site cytology was not performed. The presence of noncaseating granulomas with negative stains for mycobacteria and fungi was considered diagnostic of sarcoidosis.

Statistical Analyses

All data were analyzed using the statistical analysis software SPSS 20.0. Continuous variables were presented as mean ± standard deviation (SD) and were compared using t-test. Chi-square test was used for analysing the categorical variables. Independent-samples t- test assuming equal variance and ANOVA were performed with p < 0.05 indicated statistically signifcant. Two classifcation analysis was performed by R software.

Results General clinical data

Eighty-eight patients were included in this study with 20 cases of sarcoidosis, 23 cases of tuberculosis, 22 cases of malignancy and infammatory lymph nodes in 23 cases. There was no signifcant difference in age and sex between the sarcoidosis group and the tuberculosis group (p>0.05) as shown in Table 1. Table 3 refects the characteristics of our patients with sarcoidosis and cervical lymphadenopathy based on FNA and CNB.

Neck ultrasound (NUS) features

Table 4 shows a signifcant differences in symmetry, lymphatic hilum, homogeneity, CDFI pattern and elasticity score between the sarcoidosis and non-sarcoidosis groups statistically (p<0.05). Furthermore, specifc to sarcoidosis and tuberculosis, there were statistical differences (p<0.05) in symmetry, homogeneity, border, fusion and CDFI pattern (dendritic type was more common in the sarcoidosis group). While comparing sarcoidosis and malignancy group, there were statistically signifcant variation in symmetry and CDFI pattern (other type was more common in the malignancy group and dendritic type was more common in the sarcoidosis group). While comparing sarcoidosis with the infammatory group, there were statistically signifcant differences (p<0.05) in symmetry, longitudinal meridian, lymphatic hilum, CDFI pattern (portal type was more common in the infammatory group, and dendritic type was only observed in the sarcoidosis group) and elasticity score.

The distribution of sarcoidosis was discovered to be more bilateral when compared with non-sarcoidosis groups (18/20, 90.0% vs. 25/68, 36.8%, respectively). 100% of sarcoidosis lesion showed no lymphatic hilum, which was signifcantly different from infammatory group (p<0.05).

Contrast-enhanced ultrasound (CEUS) features

There were statistically signifcant differences in the enhanced mode of ultrasound contrast agent, homogeneity, presence or absence of necrosis between the sarcoidosis and non-sarcoidosis with further grouping them in the tuberculosis or malignancy groups which is tabulated in Table 5, Figure 1.

As to the enhanced mode of ultrasound contrast agent, the sarcoidosis group was mainly polycentric type (17/20, 85%) Figure 2a, without centripetal or annular type. However, centripetal type (Figure 2b) was more common in tuberculosis and malignancy groups (56.5%, 72.7%, respectively).

While considering the homogeneity, the perfusion in both sarcoidosis group and infammation group were 100% uniform. While mainly the perfusion of tuberculosis lymph nodes were found to be non-uniform. Similarly, while regarding the necrosis, sarcoidosis lesions were 100% without any necrosis. 19/23 (82.6%) in tuberculosis and 12/22 (54.5%) in malignancy group showed necrosis. Page 4/15 The diagnosis value of ultrasound features in Sarcoidosis vs. non-sarcoidosis

The seven characteristics were fnally entered into the two classifcation analysis model which included enhancement mode (EM), resolution time (RT), CDFI, fading time (FT), peaking state-uniformity (PTSU), strengthen the area (STA) and symmetry. The percentage correction of prediction was 90% (18/20). (Figure 3)

Discussion

Sarcoidosis is a systemic disease in which intrathoracic lymph nodes, lungs and cervical lymph nodes are also commonly involved. The application value of neck ultrasound in sarcoidosis is worth exploring. Comparing with non-sarcoidosis groups, the characteristic ultrasound imaging features of sarcoidosis include: symmetry, non-existence of lymphatics, uniformity, and dendritic CDFI pattern are more common with elasticity score ≥ 3. The characteristic CEUS imaging features of sarcoidosis include: multi-center flling, uniform lesion and without necrosis.

Sarcoidosis can affect any organ. Bilateral hilar lymphadenopathy is its characteristic manifestation often accompanied by peripheral lymph node involvement. In our study, 90.0% (18/20) of bilateral cervical lymph nodes were symmetrically enlarged in the sarcoidosis group, and were comparable to non-sarcoidosis groups which included the tuberculosis group, tumor group, and infammation group demonstrating highly signifcant statistical differences.

Normal lymphatic portal structure is formed by lymph nodes’ arteriovenous structure, fat and lymph sinus located in the central part of the lymph node. Schmid-Bindert G et al. considered that the disappearance of the lymphatic portal structure is one of the ultrasound features to identify benign and malignant lymph nodes [23]. However benign diseases such as tuberculosis and sarcoidosis of the lymph nodes can cause the destruction of the lymphatic structure. Dhorria et al. conducted a retrospective analysis of 165 patients with lymph node tuberculosis and sarcoidosis and found that the proportion of lymphatic structure involved in sarcoidosis was 13.8% and 11.4% in lymph node tuberculosis [24]. Wang and colleagues found that only 2 out of 193 cases of sarcoidosis lymph nodes had lymphadenopathy, while 11 out of 37 cases of nodular tuberculosis had lymphadenopathy, hence, considered that the absence of lymphadenopathy is an important feature of sarcoidosis [25].

In our study, there were 20 cases of sarcoidosis and NUS did not fnd any change in lymphatic structure which was signifcantly different from non-sarcoidosis group. Lymph node enlargement in the infammation group was reactive hyperplasia and the structure of the lymphatic gate was not obliterated. Theoretically, structure of the lymphatic gate should be intact in all the cases, but in 30.4% (7/23) of the cases, lymph nodes in the infammation group of this study lymphatic gate was not visible which is consistent with previous studies. According to Dudau et al., the reactive hyperplasia of lymph nodes in the cancer drainage area can be easily confused with metastatic lymph nodes [26].

In terms of ultrasound contrast agent flling methods, our results showed that the sarcoidosis group was mainly multicenter (85.0%, 17/20), and the tuberculosis group and tumor group were mainly centripetal (56.5% v.s. 72.7%, respectively) whereas the infammation group was mainly eccentric (82.6%, 19/23). Histologically, sarcoidosis was characterized by non-caseating granuloma. Within the affected lymph nodes, the usual structure was obscured by multiple distinct, "tight" and discrete granulomas [27]. The typical manifestation of granuloma was concentric rings. Therefore, when the target lymph node of the sarcoidosis group was undergoing contrast-enhanced ultrasound examination, the contrast agent was flled in a multi-center manner. In the tuberculosis group, because of necrosis or destruction of the lymphatic portal in the lymph node, and granulomatous infammatory reaction in the surrounding area, it appeared as centripetal type mode. Lymph nodes in the tumor group invaded the cortex under the lymph node capsule, causing tumor angiogenesis and lymphatic hilar vessels to shift or even disappear. The new blood vessels were mainly distributed in the marginal area of the lymph nodes, and the branches were distributed centripetally resulting in metastatic lymph nodes. For centripetal flling, the lymph nodes in the infammatory group were eccentric due to the presence of the lymphatic hilum. The contrast agent frst entered the lymph nodes from the arteries and veins of the lymph hilum then spread to the entire lymph nodes [28].

In terms of the uniformity of enhancement, both the sarcoidosis group and the infammatory nodules group showed uniform enhancement, while the tuberculosis group and the tumor group showed an uneven enhancement. The reason might be because the tuberculosis group is prone to have caseous necrosis of the lymph nodes. Likewise, for tumor group, tumor cells block the blood vessels or hypercoagulable blood leads to thrombosis.

Page 5/15 Necrosis is more common in tuberculosis and tumors. In general, sarcoidosis is not a condition to consider necrosis initially as most sarcoid granulomas are not accompanied by necrosis. Although there are individual sarcoidosis-like necrotizing granulomas reported in the previous literature. Ultrasound contrast agent is a blood pool imaging agent, which can accurately refect the microcirculation blood perfusion inside the lesion and help distinguish the necrotic area within the lesion [29].

This study preliminarily explored the application of NUS and CEUS in the diagnosis of sarcoidosis. They can refect partial vascularization forming a different impression of pseudo-ischemic area which can more truly refect the active ingredients in the lesion. In our study, 20 target lymph nodes in the sarcoidosis group showed uniform enhancement during CESU and no non-enhanced area indicated that there was no necrosis. Therefore, necrosis found through CEUS can be used to rule out sarcoidosis for differential diagnosis.

This study has the following limitations: (1) this study is a retrospective study of a single center and it is difcult to avoid the small number of cases and the deviation of the disease, (2) the prospective verifcation has not been performed to evaluate its diagnostic efcacy, (3) the authors didn’t combine the quantitative parameters obtained by CEUS time-intensity curve analysis to obtain more valuable diagnostic results. In future, a more reasonable multicenter prospective cohort study can be established to further verify the value of NUS combined with CEUS in the diagnosis of patients with sarcoidosis involving cervical lymph nodes to obtain a better result.

Conclusion

In summary, sarcoid lymph nodes displayed under conventional ultrasound and CEUS have certain specifc characteristics which are helpful for the diagnosis and differential diagnosis of sarcoidosis and have a great potential to become an important non-invasive complement to existing diagnostic methods. The ultrasound diagnosis model established by the binary classifcation algorithm helps to distinguish the diagnosis of sarcoidosis from other granulomatous non-sarcoidosis lesions such as malignancy, tuberculosis and infammatory lymph nodes.

Abbreviations

Neck ultrasound NUS

Contrast-enhanced ultrasound CEUS

Fine-needle aspiration FNA

Core needle biopsy CNB

Enhanced mode EM

Resolution time RT

Color Doppler Flow Imaging CDFI

Fading time FT

Peaking state-uniformity PTSU

Strengthen the area STA

Location, number and size LNS

Tuberculosis TB

Standard deviation SD

Analysis of variance ANOVA

Declarations

Page 6/15 Acknowledgements

The authors thank Dr. A Zhang (School of Medicine, Tongji University, Shanghai, China) and Dr. Bhavana Rajbanshi (School of Medicine, Tongji University, Shanghai, China) for their helpful contribution. We also thank our patients for their cooperation.

Ethical Approval

The study protocols were approved by the Institutional Review Boards of Shanghai Pulmonary Hospital (Approval No: k18-144).

Funding

This study was funded by the National Science Foundation of China (No: 81500052), Clinical Research Youth Project of Shanghai Health Commission (20204Y0383) and Clinical Research Foundation of Shanghai Pulmonary Hospital (fk1940 and FKLY20015).

Confict of Interest

The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.

Informed Consent

Written informed consent was obtained from all subjects (patients) in this study.

Availability of data and materials

All data regarding the included participants during the study are available from the corresponding author by email request.

Consent for publication

Not applicable.

Author contribution

MS, YW and YZ designed the study; MS, WG, and YZ assisted with patient management and follow-up; MS, WG, CY and YZ collected data and analyzed results; MS, YW and YZ wrote the manuscript.

References

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Page 7/15 6. Zhou Y, Lower EE, Li H, Baughman RP. Clinical management of pulmonary sarcoidosis. Expert Rev Respir Med. 2016;10(5):577– 591. doi:10.1586/17476348.2016.1164602 7. Wessendorf TE, Bonella F, Costabel U. Diagnosis of Sarcoidosis. Clin Rev Allergy Immunol. 2015;49(1):54–62. doi:10.1007/s12016- 015-8475-x 8. Valeyre D, Bernaudin JF, Uzunhan Y, et al. Clinical presentation of sarcoidosis and diagnostic work-up. Semin Respir Crit Care Med. 2014;35(3):336–351. doi:10.1055/s-0034-1381229 9. Lohela P, Tikkakoski T, Strengell L, et al. Ultrasound-guided fne-needle aspiration cytology of non-palpable supraclavicular lymph nodes in sarcoidosis. Acta Radiol Stockh Swed 1987. 1996; 37:896–899. 10. Stjernberg N, Thunell M, Lundgren R. Comparison of fexible fberoptic bronchoscopy and scalene lymph node biopsy in the diagnosis of sarcoidosis. Endoscopy. 1983; 15:300–301. 11. Truedson H, Stjernberg N, Thunell M. Scalene lymph node biopsy. A diagnostic method in sarcoidosis. Acta Chir Scand. 1985; 151:121–123. 12. Ahmed M, Daneshvar C, Breen D. Neck Ultrasound for the Detection of Cervical Lymphadenopathy in Sarcoidosis: An Alternative to Endobronchial Ultrasound. J Bronchology Interv Pulmonol. 2019;26(3):225–227. 13. Halpern EJ, Rosenberg M, Gomella LG. Prostate cancer: contrast-enhanced us for detection. Radiology. 2001;219(1):219–225. 14. Ladam-Marcus V, Mac G, Job L, Piot-Veron S, Marcus C, Hoeffel C. Contrast-enhanced ultrasound and liver imaging: review of the literature. J Radiol. 2009;90(1 Pt 2):93–106. 15. Hirooka Y, Itoh A, Kawashima H, et al. Contrast-enhanced endoscopic ultrasonography in digestive diseases. J Gastroenterol. 2012;47(10):1063–1072. 16. Cox K, Sever A, Jones S, et al. Validation of a technique using microbubbles and contrast enhanced ultrasound (CEUS) to biopsy sentinel lymph nodes (SLN) in pre-operative breast cancer patients with a normal grey-scale axillary ultrasound. Eur J Surg Oncol. 2013;39(7):760–765.] 17. Poanta L, Serban O, Pascu I, Pop S, Cosgarea M, Fodor D. The place of CEUS in distinguishing benign from malignant cervical lymph nodes: a prospective study. Med Ultrason. 2014;16(1):7–14. 18. Rubaltelli L, Beltrame V, Scagliori E, et al. Potential use of contrast-enhanced ultrasound (CEUS) in the detection of metastatic superfcial lymph nodes in melanoma patients. Ultraschall Med. 2014;35(1):67–71. 19. Dudau C, Hameed S, Gibson D, et al. Can contrast-enhanced ultrasound distinguish malignant from reactive lymph nodes in patients with head and neck cancers? Ultrasound Med Biol. 2014;40(4):747–754. 20. Liu H, Xiao J. Flow imaging of residual neck lymph nodes in nasopharyngeal carcinoma by contrast-enhanced ultrasonography after radiotherapy. Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2012;35(8):861–863. 21. Sumi M, Ohki M, Nakamura T. Comparison of sonography and CT for differentiating benign from malignant cervical lymph nodes in patients with squamous cell carcinoma of the head and neck. AJR Am J Roentgenol. 2001;176(4):1019–1024. 22. Itoh A, Ueno E, Tohno E, et al. Breast disease, clinical application of US elastography for diagnosis[J]. Radiology, 2006, 239(2): 341– 350. 23. SCHMID-BINDERT G, JIANG H, KÄHLER G, et al. Predicting malignancy in mediastinal lymph nodes by endobronchial ultrasound: A new ultrasound scoring system[J]. Respirology, 2012, 17(8): 1190–1198. 24. DHOORIA S, AGARWAL R, AGGARWAL A N, et al. Differentiating tuberculosis from sarcoidosis by sonographic characteristics of lymph nodes on endobronchial ultrasonography: a study of 165 patients[J]. Journal of Thoracic & Cardiovascular Surgery, 2014, 148(2): 662–667. 25. WANG L, WU W, TENG J, et al. Sonographic Features of Endobronchial Ultrasound in Differentiation of Benign Lymph Nodes[J]. Ultrasound in Medicine & Biology, 2016, 42(12):2785–2793. 26. Dudau C, Hameed S, Gibson D, et a1. Can contrast-enhanced ultrasound distinguish malignant from reactive lymph nodes in patients with head and neck cancers? [J]. Ultrasound Med Biol, 2014, 40(4):747–754. 27. Asano S. Granulomatous lymphadenitis. J Clin Exp Hematopathol.2012;52(1):1–16. 28. Dudau C, Hameed S, Gibson D, et al. Can contrast- enhanced ultrasound distinguish malignant from reactive lymph nodes in patients with head and neck cancers? [J]. Ultrasound Med Biol, 2014, 40(4): 747–754. 29. Gorg C. Transcutaneous contrast-enhanced sonography of pleural-based pulmonary lesions. Eur J Radiol, 2007, 64(2): 213–221.

Page 8/15 Tables

Table 1

Demographic information of subjects recruited

Category Sarcoidosis Group Control Subjects

Tuberculosis Group Malignancy Infammatory

Group Group

Total subjects, n 20 23 22 23

Age, years 47.1±12.7 44.1±15.0 65.6±10.0 57.5±6.2

Gender

Male 9（45.0%） 9（39.1%） 17（77.3%） 13（56.5%）

Female 11（55.0%） 14（60.9%） 5（22.7%） 10（43.5%）

CXR stage 0/4/7/0/0 N/A N/A N/A

0/I/II/III/IV §

Biopsy (cases/needles)

NUS FNA 20/20 23/23 22/22 23/23

NUS CNB 20/17 23/23 22/22 23/20

Ebus/TBLB 19/19 18/18 20/20 20/20

Surgical biopsy 3/3 0/0 2/2 0/0

Lung biopsy 12/12 23/23 22/22 10/10

CXR = chest X-ray; N/A = not applicable; CXR stage: 0 = no adenopathy, no lung infltrates; stage I = hilar & mediastinal adenopathy only; stage II = hilar & mediastinal adenopathy plus lung infltrates; stage III = lung infltrates only; stage IV = pulmonary fbrosis.

Table 2

Elasticity scoring system

Score Performance

0 the focus area is mainly cystic components, showing red, blue and green alternately

1 the lesion area and the surrounding tissue are uniformly green

2 the focus area is mainly green (green area﹥90%)

3 the focus area is messy blue-green or mainly blue (blue area is 50%~90%)

4 the lesion area is almost blue covered (blue area﹥90%)

Table 3

Characteristics of patients with sarcoidosis and cervical lymphadenopathy

Page 9/15 No. Size of Cervical LN* Side of Cervical LN Thoracic LN FNA Result CNB Result

1 18 Right Yes Adequate but nondiagnostic Diagnostic

2 9 Bilateral Yes Adequate but nondiagnostic Diagnostic

3 14 Bilateral Yes Adequate but nondiagnostic Diagnostic

4 18 Bilateral Yes Adequate but nondiagnostic Diagnostic

5 13 Bilateral Yes Adequate but nondiagnostic Diagnostic

6 8 Bilateral Yes Adequate but nondiagnostic Diagnostic

7 8 Bilateral Yes Adequate but nondiagnostic Diagnostic

8 11 Bilateral Yes Adequate but nondiagnostic Diagnostic

9 7 Right Yes Adequate but nondiagnostic Not done

10 10 Bilateral Yes Adequate but nondiagnostic Diagnostic

11 13 Bilateral Yes Diagnostic Diagnostic

12 7 Bilateral Yes Adequate but nondiagnostic Not done

13 11 Bilateral Yes Adequate but nondiagnostic Diagnostic

14 8 Bilateral Yes Adequate but nondiagnostic Diagnostic

15 9 Bilateral Yes Adequate but nondiagnostic Diagnostic

16 12 Bilateral Yes Adequate but nondiagnostic Diagnostic

17 15 Bilateral Yes Adequate but nondiagnostic Not done

18 8 Bilateral Yes Adequate but nondiagnostic Diagnostic

19 17 Bilateral Yes Adequate but nondiagnostic Diagnostic

20 14 Bilateral Yes Adequate but nondiagnostic Diagnostic

*Diameter of largest lymph node on ultrasound was in millimeter.

CNB, core needle biopsy; FNA, fne-needle aspiration; LN, lymph node.

Table 4

Neck ultrasound (NUS) features in sarcoidosis vs. non-sarcoidosis groups

Page 10/15 Category Sarcoidosis Control Subjects P Group value4 Tuberculosis P Malignancy P Infammatory P Total Group value1 value2 value3 Group Group

Symmetry

Bilateral 18（90.0%） 5(21.7%) <0.001 10（45.5%） 0.002 10（43.5%） 0.001 25(36.8%) <0.001

Unilateral 2（10.0%） 18(78.3%) 12（54.5%） 13（56.5%） 43(63.2%)

Number

1 0（0） 0(0) - 1（4.5%） 1.000 5（21.7%） 0.082 6(8.8%) 0.383

>1 20（100%） 23(100%) 21（95.5%） 18（78.3%） 62(91.2%)

Longitudinal meridian（mm）

≥10 12（60.0%） 19(82.6%) 0.099 19（86.4%） 0.052 3（13.0%） 0.001 41(60.3%) 0.981

<10 8（40.0%） 4(17.4%) 3（13.6%） 20（87.0%） 27(39.7%)

Aspect ratio

<2 14（70.0%） 19(82.6%) 0.539 20（90.9%） 0.361 13（56.5%） 0.362 52(76.5%) 0.557

≥2 6（30.0%） 4(17.4%) 2（9.1%） 10（43.5%） 16(23.5%)

Lymphatic hilum

Presence 0（0） 1(4.3%) 1.000 0（0） - 16（69.6%） <0.001 17(25.0%) 0.030

Absence 20（100%） 22（95.7%） 22（100%） 7（30.4%） 51(75.0%)

Echo

Hyperechoic 0（0） 1（4.3%） 1.000 0（0） - 0（0） - 1(1.5%) 0.513

Hypoechoic 20（100%） 22（95.7%） 22（100%） 23（100%） 67(98.5%)

Homogeneity

Uniform 15（75.0%） 3（13.0%） <0.001 12（54.5%） 0.167 15（65.2%） 0.486 30(44.1%) 0.015

Non-uniform 5（25.0%） 20（87.0%） 10（45.5%） 8（34.8%） 38(55.9%)

Border

Clear 20（100%） 13（56.5%） 0.003 21（95.5%） 1.000 23（100%） - 57(83.8%) 0.124

Unclear 0（0） 10（43.5%） 1（4.5%） 0（0） 11(16.2%)

Calcifcation

Presence 0（0） 4（17.4%） 0.152 0（0） - 0（0） - 4(5.9%) 0.617

Absence 20（100%） 19（82.6%） 22（100%） 23（100%） 64(94.1%)

Fusion

Presence 0（0） 9（39.1%） 0.006 0（0） - 0（0） - 9(13.2%) 0.194

Absence 20（100%） 14（60.9%） 22（100%） 23（100%） 59(86.8%)

CDFI pattern

Portal 3（15.0%） 2（8.7%） 0.027 0（0） 0.001 17（73.9%） <0.001 19(27.9%) <0.001

Dendritic 9（45.0%） 2（8.7%） 1（4.5%） 0（0） 3(4.4%)

Annular 1(5.0%) 4（17.4%） 0（0） 0（0） 4(5.9%)

Page 11/15 Other 7(35.0%) 15（65.2%） 21（95.5%） 6（26.1%） 42(61.8%)

Elasticity score

≥3 16（80.0%） 14（60.9%） 0.173 16（72.7%） 0.849 6（26.1%） <0.001 36(52.9%) 0.030

<3 4（20.0%） 9（39.1%） 6（27.3%） 17（73.9%） 32(47.1%)

CDFI: Color Doppler Flow Imaging; 1 Sarcoidosis vs. Tuberculosis Group; 2 Sarcoidosis vs. Malignancy Group; 3 Sarcoidosis vs. Infammatory Group; 4Sarcoidosis vs. Non-sarcoidosis groups.

Table 5

Contrast-enhanced ultrasound (CEUS) features in sarcoidosis vs. non-sarcoidosis groups

Category Sarcoidosis Control Subjects P Group value4 Tuberculosis P Malignancy P Infammatory P value3 Total Group value1 value2 Group Group

Enhanced mode

Centripetal 0（0） 13（56.5%） <0.001 16（72.7%） <0.001 4（17.4%） <0.001 33 <0.001 （48.5%）

Centrifugal 3（15.0%） 6（26.1%） 1（4.5%） 19（82.6%） 26 （38.2%）

Polycentric 17（85.0%） 2（8.7%） 3（13.6%） 0（0） 5（7.4%）

Annular 0（0） 2（8.7%） 2（9.1%） 0（0） 4（5.9%）

Enhanced degree

Low / equal 2（10.0%） 2（8.7%） 0.950 0（0） 0.647 0（0） 0.210 2（2.9%） 0.471

High 18（90.0%） 21（91.3%） 22（100%） 23（100%） 66 （97.1%）

Homogeneity

Uniform 20（100%） 4（17.4%） <0.001 10（45.5%） <0.001 23（100%） - 37 <0.001 （54.4%）

Non- 0（0） 19（82.6%） 12（54.5%） 0（0） 31 uniform （45.6%）

Necrosis

Presence 0（0） 19（82.6%） <0.001 12（54.5%） <0.001 0（0） - 31 <0.001 （45.6%）

Absence 20（100%） 4（17.4%） 10（45.5%） 23（100%） 37 （54.4%）

Arrival time 10.4±2.6 11.3±3.1 13.3±3.6 11.4±3.0 (s)

Peak time (s) 15.5±3.7 17.8±3.9 21.1±5.1 17.7±3.7

Wash-out 22.3±4.5 25.9±4.0 28.4±6.2 27.1±3.2 time (s)

1 Sarcoidosis vs. Tuberculosis Group; 2 Sarcoidosis vs. Malignancy Group; 3 Sarcoidosis vs. Infammatory Group; 4Sarcoidosis vs. Non-sarcoidosis groups.

Page 12/15 Figures

Figure 1

A: NUS showed right supraclavicular lymphadenopathy, and the target lymph node was hypoechoic, uniform, no lymph hilum, clear border and no fusion. B：CEUS showed that the target lymph node showed uniform and high enhancement and there was no non- enhanced area at the peak. C：Pathological specimens obtained by ultrasound-guided percutaneous biopsy showed granuloma. (Case1, a 34-year-old male) D：NUS showed right supraclavicular lymph node was enlarged, and the target lymph node was hypoechoic, non- uniform, no lymph hilum, clear border and no fusion. E：CEUS showed that the target lymph node showed non-uniform and high enhancement, and there were large irregular areas without enhancement at the peak. F：Pathological specimens obtained by ultrasound- guided percutaneous biopsy showed necrotizing granuloma. (Case2, a 22-year-old male) G：NUS showed right supraclavicular lymph node was enlarged, and the target lymph node was hypoechoic, uniform, no lymphatic hilum, clear border and no fusion. H：CEUS showed that the target lymph node showed uniform and equal enhancement, and there was no non-enhanced area at the peak. I： Pathological specimens obtained by ultrasound-guided percutaneous biopsy showed granulomatous lesions, no necrosis, acid-fast found a small number of positive bacilli, considering the possibility of tuberculous lesions. (Case3, a 49-year-old female) J：NUS showed right supraclavicular lymph node was enlarged, and the target lymph node was hypoechoic, uniform, no lymphatic hilum, clear border and no fusion. K：CEUS showed that the target lymph node showed uniform and high enhancement, and there was no non-enhanced area at the peak. L：Pathological specimens obtained by ultrasound-guided percutaneous biopsy showed metastatic non-small cell

Page 13/15 carcinoma, tending to adenocarcinoma. (Case4, a 65-year-old male) M：NUS showed right supraclavicular lymph node was enlarged, and the target lymph node was hypoechoic, uniform, no lymphatic hilum, clear border and no fusion. N：CEUS showed that the target lymph node showed non-uniform and high enhancement, and there were small irregular non-enhanced areas at the peak. O：Pathological specimens obtained by ultrasound-guided percutaneous biopsy showed metastatic small cell carcinoma. (Case5, a 78-year-old male) P： NUS showed right supraclavicular lymph node was enlarged, and the target lymph node was hypoechoic, non-uniform, lymphatic hilum, clear border and no fusion. Q：CEUS showed that the target lymph node showed uniform and high enhancement, and there was no non- enhanced area at the peak. R：Pathological specimens obtained by ultrasound-guided percutaneous biopsy showed lymphoid tissue hyperplasia (Case6, a 60-year-old male). Hematoxylin-eosin stain was used for histopathology and magnifcation×100.

Figure 2

A: CESU manifestation of sarcoidosis is that the enhancement pattern is polycentric. B: the metastatic lymph node of lung cancer is centripetal.

Page 14/15 Figure 3

A: 25 characteristics from NUS and CEUS were considered for diagnosis analysis. B, C: Seven most signifcant characteristics were entered into the two classifcation analysis model. D: The percentage correction of prediction was 90%

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